An Organic Transistor-based Electrical Assay for Copper(II) in Water

Abstract

We herein report an electrical assay for copper(II) (Cu²⁺) utilizing an organic thin-film transistor (TFT). To endow the metal ion recognition ability, the extended-gate portion in the organic TFT is functionalized by a nitrilotriacetic acid (NTA)-terminated monolayer. As a result, the device responds selectively to Cu²⁺ in aqueous media. Importantly, the estimated detection limit for Cu²⁺ (= 96 ppb) is much lower than environmental standard value of a copper contaminant in drinking water. Its superior processability and portability in the organic device indicate that the proposed assay could be applied for on-site detection of the Cu²⁺ ion without large-sized equipment.